Field of the Disclosure
The present disclosure relates to a display device, and more particularly to a backlight unit and a display device including the backlight unit.
Discussion of the Related Art
A related art LCD device uses optical anisotropy and polarization properties of liquid crystal molecules. The transmissivity of the liquid crystal molecules is changed by an electric field such that the LCD device displays images.
As shown in FIG. 1, which is a schematic cross-sectional view of the related art LCD device, the LCD device includes a liquid crystal panel 10, a backlight unit 20, a bottom frame 30, a main frame 40, and a top frame 50.
The liquid crystal panel 10 includes a thin film transistor (TFT) substrate 12, a color filter substrate 14 facing the TFT substrate, and a liquid crystal layer (not shown) therebetween.
First and second polarizing plates 16 and 18 are attached on lower and upper sides of the liquid crystal panel 10.
The backlight unit 20 includes a reflective sheet 21, a light source 23, a light guide plate 25, an optical sheet 27, and a housing 29 supporting the light source 23.
The reflective sheet 21 reflects the light leaked from the light guide plate 25 toward the liquid crystal panel 10.
The light source 23 includes a printed circuit board (PCB) 23a and a light emitting diode (LED) 23b. An external voltage is supplied to an LED package by the PCB 23a. 
The light guide plate 25 provides the light from the light source 23 into the liquid crystal panel 10. The light guide plate 25 may be formed of poly methyl methacrylate (PMMA) or glass.
The light from the light guide plate 25 is diffused and concentrated by the optical sheet 27 and is provided onto the liquid crystal panel 10.
The bottom frame 30 has a space for the light source 23, the reflective sheet 21, the light guide plate 25 and the optical sheet 27. In addition, the bottom frame 30 supports the main frame 40.
The main frame 40 supports the liquid crystal panel 10. The main frame 40 may include a panel supporting part for supporting the liquid crystal panel 10 and a side wall covering the backlight unit 20.
The top frame 50 covers front edges of the liquid crystal panel 10 and a side of the main frame 40 and the bottom frame 30.
In the related art LCD device, the light source 23 includes the LED package, and the light guide plate 25 includes glass.
Due to the properties of the material of the light guide plate 25, a difference in the color coordinate and the color sense between a first side of the light guide plate 25, which faces the light source 23, and a second side of the light guide plate 25, which opposite to the first side, is generated. As a result, the image quality of the LCD device is degraded.